The need for efficient means for the considerate disposal of waste products has long been addressed. Landfills have been utilized as the least expensive manner for disposal since it requires no more than the collection and transport of the material to the site. This procedure has been followed in many areas which still have sufficient open areas available. However, several factors preclude the employment of landfills. Less and less space now exists in many countries, particularly in and adjacent to urban areas, which areas obviously generate the greatest volume of waste material. Additionally, ever increasing environmental controls are forcing many jurisdictions to seek alternate means for waste disposal.
In the case of inorganic matter, it is known to recycle many materials such as glass and metals and the processes for handling these offer little environmental concern. On the other hand, the disposal of waste organic matter has been known to raise many objections. In a landfill, many waste organic materials may discompose and yield harmful products capable of contaminating the soil and ground water. Other organic wastes, such as vehicle tires and the myriad of plastics products, exhibit little or no decomposition in a landfill and more importantly, are difficult to bury. These latter wastes, in view of their resiliency, tend to work their way to the surface of any manipulated landfill. Many dumps devoted exclusively to tires are located throughout the country--some containing several million tires each. When these have caught on fire, it has often taken several weeks to extinguish the smoldering blaze with a most objectionable emission usually spreading over tens of thousands of acres.
Several states and other jurisdictions have totally outlawed any further landfills. This action dictates that new means must be provided to accommodate the disposal of at least those organic materials which heretofore mostly have been relegated to a landfill or the like. With over 200 million tires being used annually in this country alone, it follows that any disposal method which can utilize tires as an infeed and which yields valuable by-products, will present a unique advancement of the art.